已知tanx=-3/4,求2sin^2 x+3sin xcos x-cos^2 x
(1-(sin^4x-sin^2xcos^2x+cos^4x)/sin^2x +3sin^2x
sin^2x+cos^2x)(sin^4x-sin^2xcos^2x+cos^4x) =sin^4x-sin^2xcos
已知tanX=2求2sin^2X+sinXcosX-3cos^2X
已知tanx=-0.5,求sin^2x+2sinxcosx-3cos^2x的值,
已知tanx=1/2,求sin x-cos x/2sinx+3cosx的值
已知tanx=2,(1)求2/3sin^2x+1/4cos^2x的值(2)求2sin^2x-sinxcosx+cos^2
三角函数题.已知tanx=2.求(sin(π-x)cos(2π-x)sin(-x+3π/2))/tan(-x-π)sin
求函数f(x)=(sin^4x+cos^4x+sin^2xcos^2x)/2
已知(1+tanx)/(1-tanx)=3+根号二,求cos²x+sinxcosx+2sin²x的值
已知(1+tanx)/(1-tanx)=3 求(sin^2x+2sinx·cosx-cos^2x)/(sin^2x+2c
求函数y=2sin xcos x+2sin x+2cos x+4的值域
已知tanx=3,求(2/3)sin^2x+(1/4)cos^2x的值